Research On Geological Prediction Ahead For The Karst In Maluqing Tunnel

Advanced geological prediction is regarded as a very important process in tunnel construction. It is of common occurrence that the geological hazard happens in tunnel construction for the design institute and construction organization's less attention on geological task. To make accurate geological condition prediction anterior to tunnel face in tunnel construction, by using engineering geology as basic theory and supervising method, combined with all kinds of advanced geological detection Technique, is a very important task in tunnel construction.Based on the background of Yichang-Wanxian railway at Maluqing tunnel, firstly, make an analysis of main geological feature of the tunnel site and discuss the detecting methods to hidden karst structure. Advanced geological prediction method combined with remote distance TSP advanced geological prediction and short distance ground-penetrating radar detecting is put forward. It can make an accurate detection to suddenly gushing water hazards. Secondly, by analyzing the hazard of suddenly gushing water and mud occurred in right line of Maluqing tunnel, the results show that karst structure occurred in shallow-buried and high-weathering rock mass provides the channel and storage space for suddenly gushing water in tunnel, furthermore, a favorable geological condition for geological hazards such as suddenly gushing water is created. By using TSP-203+ advanced geological prediction, the detecting results conducted in construction site show that there are two hidden water-bearing cavities structure occurred in left line of Maluqing tunnel. Finally, taking detected result with TSP-203+ advanced geological prediction, surrounding rocks conditions and geological features into consideration, an advanced geological prediction model of hidden water- bearing cavities structure in tunnel is put forward, and make a prediction for the most possible areas which contain hidden water-bearing cavities occurred in left line of Maluqing tunnel. The results detected after excavation show that the prediction made by advanced geological prediction model is accurate and acceptable.